From 71f6bd4a23130cd2f4b036010c5790b1295290b9 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 30 Jan 2012 12:25:24 +0100 Subject: [PATCH] PCI: workaround hard-wired bus number V2 Fixes PCI device detection on IBM xSeries IBM 3850 M2 / x3950 M2 when using ACPI resources (_CRS). This is default, a manual workaround (without this patch) would be pci=nocrs boot param. V2: Add dev_warn if the workaround is hit. This should reveal how common such setups are (via google) and point to possible problems if things are still not working as expected. -> Suggested by Jan Beulich. Cc: stable@vger.kernel.org Tested-by: garyhade@us.ibm.com Signed-off-by: Yinghai Lu Signed-off-by: Jesse Barnes --- drivers/pci/probe.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 7cc9e2f0f47c..71eac9cd724d 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -651,6 +651,11 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, dev_dbg(&dev->dev, "scanning [bus %02x-%02x] behind bridge, pass %d\n", secondary, subordinate, pass); + if (!primary && (primary != bus->number) && secondary && subordinate) { + dev_warn(&dev->dev, "Primary bus is hard wired to 0\n"); + primary = bus->number; + } + /* Check if setup is sensible at all */ if (!pass && (primary != bus->number || secondary <= bus->number)) { -- 2.20.1